Separation of organic compounds



March 24, 1953 H, G, McGRA-rH SEPARATION oF ORGANIC COMPOUNDS 2SHE'ET's-SHEET 1 'Filed Feb. 27, 194,7

H. G. MCGRATH SEPARATION OF ORGANIC COMPOUNDS March 24, 1953 SHEETS-SHEET 2 Filed Feb. 27, 1947 INVENTOR HENRY G. MCG'RATH BY c jf.

Y supplied through line II.

vapor form substantially as it comes from the Patented Mar. 24, 1953SEPARATION OF ORGANIC COMPOUNDS Henry ancorata Euzaheth, N. J., assighorto The M. W. Kellogg Company, Jersey City, N. J., a corporation ofDelaware Application February 27, 1947, Serial No. 731,269

8 Claims.

This invention relates to the separation of organic compounds andrelates more particularly to the separation of oxygenated organiccompounds from the reaction product obtained in the catalytichydrogenation of oxides of carbon at elevated temperatures. Still moreparticularly, the invention relates to an improved process for theseparation and recovery of useful oxygenated organic compounds presentin the reactor gas obtained in the hydrogenation of Oxides of carbon inthe'presence `of a reducible `metal catalyst. These compoun-ds comprise,es-

sentially, light and heavy alcohols and organic acids, esters,raldehydes, `ketones and also hydroj carbons.

It is an object, and the Aprocess of this invention is directed, toprovide for an improved method for the separation of oxygenated organiccompounds present in the reactor gas obtained in the catalytichydrogenation of oxides of carbon, in order to effect eicient andeconomical recovery of relatively high yields of such compounds. Otherobjects and advantages will be apparent `from the following moredetailed disclosure. Y

Thewaccompanying drawing illustrates, diagrammatically, one form of theapparatus employed and capable of carrying out one embodiment of theprocess of the invention. rThe invention will be described in detail byreference to a process employing the apparatus illustrated in thedrawing, but it should be noted that it is not intended that theinvention be limited to the-embodimentas illustrated but is capable ofother embodiments which may extend beyond the scope ofv the apparatusillustrated in the drawing. Furthermore, the distribution andcirculation of liquids and vapors is illustrated in the drawing bydiagrammatic representation of the apparatus employed. Valves, pumps,compressors, coolers and other mechanical elements necessary to effectthe transfer of liquids an-d vapors and to maintain the conditions oftemperature and pressure necessary to carry out the function of theapparatus are omitted, in order torsimplify the description. It will beunderstood, however, that much equipment of this nature is necessary andwill be supplied by those skilled in the art.

Referring to the drawing, the product of the reaction of an oxide ofcarbon and hydrogen is This product is in reactor at temperaturesvarying between approximately 300 F. to 700 F. and is'rst cooled tocondense substantially large quantities of normally liquid components.Conveniently, condensation may be effected in a plurality of coolingstages which are represented diagrammatically in the drawing by coolerI2 with which connects with line I6 for combining the scrubbing' line IIconnects. From cooler I2 the mixture cf condensate and uncondensed gaspasses through line I3 to a separator I4. In the latter, the gases arewithdrawn through line I5 and the condensate separates as a loweraqueous phase :and an upper oil phase. Both phases, thus obtained,contain oxygenated organic compounds, those of lower molecular weighttending to remain in the aqueous phase, While those of higher molecularweight tend to remain in the oil phase. VThe aqueous phase is drawn offfrom the bottom of separator I4 through line IG, and the oil phase isdrawn off at an intermediate point through line I'I. It should be notedthat apparatus embodying more than one separation stage maybe employedif desired; for example, primary and secondary separation stages may beintroduced operating successively and respectively at temperatures ofabout F. and `00 F.

The gases separated in separator I4 are through line I5 to a low pointin a suitable scrubbing vessel I8. In this gas scrubber, the gases areintimately contacted with water or with an aqueous solution containingoxygenated organic compounds introduced through line I9, in order toabsorb the more volatile oxygenated com-j pounds in the Water. Theremaining gas, essentially free of oxygenated compounds andconsistingessentially of light hydrocarbons, is withdrawn overhead through line 20for further treatment or use outside the scope of the present process. f

The oil phase separated in separator I4, is

transferred through line I'I to a low point in an the oxygenatedcompounds which are dissolved in the oil and are relatively more solublein water, such as low boiling alcohols, ketones, aldehydes, and acids.The water employed for this purpose conveniently may be the wateremployed for scrubbing in gas scrubber I8, which is transferred fromscrubber I8 tothe upper part'of oil scrubber 2| through line 22. Thescrubbing water, containing dissolved oxygenated compounds, is withdrawnfrom the bottom of oil scrubber 2l through line 23, which convenientlyWater with the 4water phase Withdrawn from separator I4. It is alsopossible to transfer the Water, withdrawn from scrubber I8 through line22, directly into une I6, through une 22u` with which line I6 connects.

The scrubbed oil is Withdrawn oVerhe-adirom oil scrubber 2| through une24. `This 011, comprising essentially a mixture of organic acids,alcohols, esters, aldehydes, ketones and hydrocarbons is transferredthrough line 24 to a low pomt in an extraction tower 25. In tower 2:5,

passed the oil introduced through line 24 is subjected to intimatecountercurrent contact with a light alcohol as a treating agent, such asmethanol or ethanol, which is introduced into tower 25 at an upper pointthrough line 23. The treating agent and the oil introduced through line2li, are contacted in tower 25 under conditions eifective to absorb inthe treating agent substantially all of the oxygenated compoundscontained in the oil and thus separate these oxygenated compounds fromhydrocarbons present. As a result of such treatment, a lower aqueousalcohol layer and an upper hydrocarbon or oil layer are formed in tower25. Inasmuch as anhydrous light alcohols exhibit high solubilities forhydrocarbons as well as for oxygenated compounds, dilution of suchalcohols will effect an improvement in the selectivity of extraction, sothat absorption of hydrocarbons in the alcohol treating agent issubstantially prevented. To obtain such dilution, water is introducedinto tower 25 at an upper point above the alcohol inlet through line 2.The use of water in the manner described is effective not only for thepurpose of alcohol dilution, but its introduction at an upper point intower 25, accomplishes the result of washing the upper hydrocarbon oroil layer free of the added alcohol treating agent.

Aqueous methanol, used as a treati-ng agent in the instant example isnot, however, completely selective in effecting total extraction ofoxygenated organic compounds lfrom hydrocarbons present in tower 25.Hence, `the liquid flowing down tower 25 will con-tain some hydrocarbonsin solution in addition to oxygenated organic compounds. Thesehydrocarbons may comprise a mixture of proportionately small quantitiesof all the hydrocarbons present in the oil stream entering tower 25through line 2d and would render subsequent separation of pureoxygenated compounds highly diiiicult. A light hydrocarbon stream,functioning as a wash-oil, is therefore introduced at a point near thebottom 'of tower 25 through line 23. This hydrocarbon stream effects thewashing -of the lower aqueous methanol layer in tower 25, free ofhydrocarbons contained therein, in that these hydrocarbons are displacedby dilution, leaving the methanol layer saturated with the wash-oil. Itis Vdesirable that this wash-oil be of such composition that there areno components present in a substantial amount, Ithat are heavier thanthe highest boiling hydrocarbon which forms an azeotrope with thealcohol treating agent. The boiling point of the wash-oil selected must,therefore, be .substantially within or below the boiling range of theoxygenated compounds that are to be separated. Following theabove-mentioned wash-oil treatment, there is present in tower 25 ranupper hydrocarbon vor oil layer containing Substantially all thehydrocarbons that were present in the oil stream entering tower 25through line 24 andsubstantially large quantities of the wash-oil, andthere is also present a lower aqueous methanol layer saturated withwash-oil and containing extracted oxygenated compounds. The upperhydrocarbon or cil layer is withdrawn overhead as a rafnate from tower25 through line 29 and is in condition for further use or treatmentoutside the scope of the present process. The lower aqueous methanollayer from tower 25 is withdrawn as an extract throughV line 30. Itshould be noted that it is also possible to transfer the aforementionedoil phase from separator I4 directly into tower 25 through line 4 3|,by-passing tower 2l, for treatment in the process described above. Wheresuch procedure is employed, low boiling alcohols, ketones and aldehydesare subjected to treatment in tower 25 together with higher boilingcomponents present in the oil phase obtained from separator I4 andwithdrawn through line Il.

The lower aqueous methanol layer from tower 25, saturated with wash-oiland containing oxygenated compounds, is transferred through line 30 to afractionation tower 32. Tower 32, functioning as a methanol stripper, isoperated under conditions effective to separate the aqueous methanollayer, introduced from tower 25 through line 30, into an overheadalcohol fraction comprising essentially methanol and hydrocarbons whichis withdrawn through line 26, and a lower fraction normally consistingof two phases, one phase comprising substantially oxygenated compoundsand the other phase comprising substantially water, containing somedissolved oxygenated compounds. These combined phases are withdrawn asbottoms through line 33. The overhead alcohol fraction from tower 32 iswithdrawn through line 25 as a vapor, and is cooled to liquefy methancland hydrocarbon components. The mixture of methanol and hydrocarbonsthus liquefied, is transferred through line 26 into tower 25 forArepeated use as the methanol treating agent in the process hereinbeforedescribed. Make-up methanol is introduced through line 26 through line34 with which line 26 connects. Bottoms from tower 32, comprisingessentially an aqueous mixture of dissolved oxygenated compounds,namely, heavy alcohols, aldehydes, ketones, and lesser amounts oforganic acids and esters, are transferred through line 33 to a settler35. In settler 35, separation is effected between the aforementionedoxygenated compounds which are withdrawn through line 36 as an upper oillayer, and a lower water layer which is withdrawn through line 3l forfurther use in the process hereinafter described.

The above-mentioned oxygenated compounds. withdrawn as an upper oillayer from settler 35 are transferred through line 36 to a caustictreater 38. In treater 38, the oil layer introduced through line 36 istreated with alkali to neutralize any traces of organic acids presentthat were not removed by the alcohol treating agent in tower 25, andsuch alkali may also be introduced in increased quantities undersuitable conditions of temperature effective to saponify esters orpolymerize aldehydes. Alkali thus employed, converts organic acidscontained in the oil layer to their corresponding organic salts. Forthis purpose, the oil, thus introduced into tower 38, is intimatelymixed with alkali, in a suitable amount, introduced into tower 38 at anupper point through line 39. In order to facilitate separation of excessalkali and the Various reaction products from the oil, the mixture ofoil and alkali is contacted with water introduced into treater 3S at anupper point above the introduction of the alkali, through line 43. Theamount of water is limited to the minimum necessary to effect suitableseparation of the alkali from oil and other reaction products. In orderto facilitate separation of organic salts present in the Oil, which wereobtained in the above-mentioned conversion from their correspondingacids, a light hydrocarbon stream, such as n-pentane used as a treatingagent, is introduced at a point near the bottom of tower 38 products intower 38.

through line 4l. rlhe adrnixture of the intro` duced hydrocarbon streamwith salts of organic acids present in the oil, tends to confine thesesalts in the lower aqueous alcohol layer which is present in treater 38.The introduction of the aforementioned light hydrocarbon stream throughline "4l,` has the additional vadvantage of permittingv the use ofstrong caustic solutions in the process described above, withoutincreasing the quantity of water required for separating the oil fromalkali and other reaction Hence, as a result of treatment of the oilintroduced into treater 38 through line 36, in the process describedabove, there `are present in tower 38 an upper hydrocarbon oroil layerwhich is` withdrawn overhead through line 42 and a lower aqueous alcohollayer containing salts of organic acids, which is withdrawn as bottomsthrough line 43 for further use or treatment in the process hereinafterdescribed.

The upper hydrocarbon or oil layer from treater 38, containinghydrocarbons, alcohols, aldehydes and ketones is transferred throughline 42 to a distillation tower 44. Tower 44 is provided and suitablyequipped to separate the oil into relatively low and highboilinghydrocarbon fractions. This tower is operated under conditions effectiveto separate the oil into an upper fraction, containing vaporized lighthydrocarbons, and a lower fraction, comprising alcohols, aldehydes andketones. The vaporized light hydrocarbons in tower 44 are withdrawnthrough line 4 l cooled to liquefy components present, and transferredto treater 38 for use as a treating agent in the process hereinbeforedescribed. Make-up treating agent is introduced into tower 38 throughline 45 with which line 4| connects. The lower fraction from tower 44,comprising alcohols, aldehydes and ketones, is withdrawn through line 46and may be transferred through line 41, with which line 4EV connects,for further` treatment outside the scope of the present process. toobtain separation of individual components. It is also possible topassthe overhead oil layer which is withdrawn from treater 38 throughline 42, directly to the aforementioned 1 aldehyde ketone recoverysystem through line 41 with which line 42 connects (bypassing tower 44),in order to obtain separation of individual aldehyde and ketonecomponents.

. It will be noted from the foregoing description that there has beenindicated the use of methanol as a treating agent, intended to absorbtherein such oxygenated compounds that may be contained in the oilstream entering tower 25 through line 24. There'also has been indicatedthe `necessity for proper aqueous dilution of the anhydrous alcohol,which exhibits high solubilities for hydrocarbone as well as foroxygenated compounds, so that improvement in selectivity of extractionmay be attained, in that absorption of hydrocarbons in the alcohol issubstantially prevented. Accordingly, it has been found that the use ofmethanol andwater, in approximate proportions of 90% methanol and water,.is highly satisfactory when` employed in the extraction of oxygenatedcompounds contained in the aforementioned oil stream entering tower 25through line 24. As alcohol concentrations are increased, the quantitiesof hydrocarbons present in the extract areY proportionately increased,by reason of the reduced selectivity of the alcohol. An increase inthequantities of wash-oil used to removeA these hydrocarbons from theextract, may therefore be necessary. `On the other hand,` as the alcoholconcentrations are decreased, quantities of Wash' oil required to removehydrocarbons present in the extract, are also proportionately reduced byreason cf increased selectivity in the alcohol. However, excessivedilution may result in incomplete extraction of oxygenated compounds andwill, therefore, necessitate an increase in the quantities of aqueousalcohol in circulation. It will, therefore, be noted that optimumbenefits will lie in the combined use of a wash-oil and an aqueousalcohol of such concentration which, from an economical standpoint, willrender the most substantial selectivityof the alcohol in ef' fectingtotal extraction of oxygenated compounds from hydrocarbons. It will,therefore, be apparent that the principal operating variables in tower-25 are the rate of alcohol circulation, alcohol concentration and rateof wash-oil circulation. In

effecting a given extraction, one or more of these variables may bechanged, if a compensatory change is made in one or more of the othervariables. The most economical combination will be chosen for any givencase. It should .be noted, however, that the combination chosen mayobviously be different as between different feed-stocks.

While it is preferred to use methanol as an over-all generally suitabletreating agent in the process described, other light alcohols such asethanol or propanol may also be successfully employed. Ethanol andpropanol are less selective as solvents than methanol. in combinationwith increased quantities of water to improve their selectivity, maybedesirable, in that the size of tower 25 may be decreased, effectingproportionate savings in the cost of equipment. In addition, it shouldbe noted that it is possible to use a mixture of light alcohols as atreating agent in the process described, as well as individual lightalcohol treating agents. In addition, other types of alcohols, such asglycols, may be successfully used as treating agents. Furthermore, othertypes of oxygenated organic compounds or mixtures of such compoundssubstantially more volatile than the bulk of oxygenated compounds beingrecovered, may be used as treating agents. For example, such oxygenatedorganic compounds as ketones may be used, e, g.,`

acetone or methyl ethyl ketone; aldehydes e. g.,

cetaldehyde; and esters e. g., ethyl acetate or methyl acetate. Inaddition, these compounds may be employed individually or in combinationVwith the aforementioned alcohols as treating agents. In general, theselection of a suitable treating agent will depend upon the use of suchoxygenated compounds as can easily be separated from extractedchemicals.

It has beenindicated that the selection of a suitable wash-oil, in theprocess described above, is determined by using oil of such compositionthat there are no components present in substantial amounts, that areheavier than the highest boiling hydrocarbon which forms an azeotropewith the treating agent. N-pentane has been found to be generallysatisfactory as a wash-oil. However, it should be noted that otherhydrocarbons having not more than eight carbon atoms per molecule, suchas butane, hexaney heptane or octane, individually or in mixturesthereof, may be successfully employed. It is also possible :to employother classes of hydrocarbons which form an azeotrope with the solventtreating agent such as certain olens. In this respect, it should also benoted that the aforementioned light hydro-J carbon stream withdrawn fromtower 44 through line 4l for use as a wash-oil in treater-38, needHowever, their use 7. not-`v be a. closely fractionated product but mayconta-in any hydrocarbon. or combination of hydrocarbons,V that meets;thev above-mentioned requirements;

Itzwill be noted thaty the above-mentioned extraction step hasparticular merit in the use of an alcohol as aV treating agent incombination with a wash-oil as a single extraction step. The resultantsaving in cost, of equipment will be apparenti from the fact that whenthe hydrocarbon extract used as av wash-oil is mixed in one towerA withVthe aforementioned oill stream used as. a feed, any increase in thenumber of extraeT tion towers is obviated.

As described; above, the aqueous phase withdrawn as bottoms fromseparator is, contains low molecular weight oxygenated compounds,comprising chiefly, light alcohols. and light acids. In addition,relatively small quantities of aldehydes, ketones, esters and heavieracids arel also present. This aqueous phase from separator4 lli, isnext. transferred throughline It` to av distillationtower 48 whichfunctions as an. alcohol stripper. In tower de, the mixture ofoxygenated compounds is heated under proper operating conditions. oftemperature. and, pressure eeetive to distill overhead alcohols,aldehvdes, ketones, and esters.. which. are Withdrawn through line 49.Bottoms obtained from tower 48, comprising aqueous light organic acids,are withdrawn through line 5,0 for further treatment in the processhereinafter described.

The overhead from tower d8, comprising a mixture. f' light alcohols,aldehydes, ketones and esters isv transferred through line 45 to adistillatioIl` tower In, tower 5i the mixture is heated under properoperating conditions of temperature and pressure to di-still overheadthe lowest boiling componentsV of the mixture, which are acetaldehydeand propionaldehyde and which are withdrawn through line 52 for furtheruse outside the scope of this process. Bottoms obtained from tower 5i,comprising a distillate of substantially light alcohols and ketones, arewithdrawn through line 53. This distillate may contain light alcoholshaving up to six carbon atoms per' molecule, aldehydes other thanacetylalde hyde and propionaldehyde, and contains in addition, ketones,esters, traces of organic acids and water. This distillate is nexttreated with alkali in order to effect neutralization of traces oforganic acids present, and such alkali may also be introduced inincreased quantities under suitable conditions of temperature effectiveto saponiy esters or polymerize aldehydes. Forl this purpose, thedistillate is transferred from tower 5l through line 53 to a caustictreater 5d, in which it is intimately mixed with alkali in a suitableamount introduced through line 55. components of the mixture aremaintained in intimate contact for a time sufficient tor effect the.desired neutralization of traces of organic acids present in thedistillatev from tower 5i, and' to eiiect polymerization of alclehydesVand saponification ofv esters, the mixture, is withdrawn from caustictreater 54 through line 55. At this point, where so desired, it ispossible to transfer the lower aqueous layer obtained from settler 35.(through line 3l) and containing salts of heavy organic acids, directlyinto caustic treater 54, throughV line 51 with which line 311 connects,for treatment inthe process described above.v In addition, it is alsopossible to transfer the aforementioned lower aqueous layer obtainedfrom settler 35, via line 51, directly through line i5 (through linev58v with whichl line i6 connects) After theA 82 for. subsequenttreatment inftoweri in theoretess, described above.`

The mixture fromv caustic treater 54,. comprise. ing an aqueous.mixture, of salts. of heavy organic acids, aldehyde polymers,v lightalcohols, having up: to six carbon atoms per molecule,4 ketones,relatively small quantites of hydrocarbons and excess, alkali, iswithdrawn through4 line 55. The hydrocarbons presentJ in the above,mixture must be removed in; order to. eiect` the subsequent recovery. ofpure alcohols. llt` has been found thatthe hydrocarbons tend toconcentrateI as their homogeneous alcoholl azeotropes in thedistillation cuts takenbetween the. various alcohols. In such aqueousalcohol solutions,l contaminating hydrocarbons. Cari beremoyedeiiioiently and. economically by means` or one or more4 hydrocarbons.whichA are themselves. readily. removable. Irl. nrineinlethe.nltooessmav beoonsidered asomo, or dilution` rather than extraction. in.that. the.. undesirable hydrocarbons are replaced by oneA or more ofthe, aforementioned hydrocarbons that may be readily eliminated.,

Such. av hydrocarbon may be n-pentane.- which. is highly suitable inover-al1 use as applied to the aforementioned process and as evidencedby eX- perimental laboratory data., Itshould. be noted that, theoneratioriis not restrietedito the solo use of. pentane. for theYpurpose indicated., but that. other lighter or heavier hydrocarbons mayalso be successfully employed such as butane or heptane.V Butane has theadvantage of not being, known to form an azeotrope with methanol,although it has a higher solubility7 in aqueous alcohol solutions. Onthe4 other hand', itl may be desirable to use heavier hydrocarbonsr as asolvent such as hexane, the latter being less soluble thank pentane butrequiring the Stripping ofV lighter hydrocarbons out of thehexanemaswellas the strippingofhexane from the heavier hydrocarbons. Thechoice of a suitable hydrocarbon will' be iniiuenced by its solubility,and; by its boiling point or the boiling points of itsazeotropes withlight alcohols.

To eiiect the removal of suchl contaminating' hydrocarbons, the mixturefrom causticV treater 54 is transferred through line 5B toanextractiontower 59. In tower 59 the mixture introduced.V through line 56, issubjected to intimate countercurrent contact with penta-ne or otherselectedr` suitable hydrocarbon treating agent, which isintroduced intotower 59,- at alowfpoint through line 60. The treating: agent and theaforementioned: alcohol mixture, containing hydrocarbons, areA contactedinI tower 59 under condi-tionseflective to absorb; in the treatingagent, the h-ydrocarbons present. In order to reducel the solubilityofthe. treating agent in the resulting alcohol phase produced in tower59, asl well as toreduce the pentanev requirements for eirecting totalextraction of' contaminating hydrocarbons, Water may be introduced intoltower 59 at an upper pointthrough line 61. The bottoms thus produced intower 59, comprising anaqueous mixture of alcohols having up tosixcarbon` atoms Der moleculey salts of heavy organic acids, ketones,excess; alkali anda portion of the# pentane treating agent, is Withdrawnas` bottoms. through line 6 2 for; further-treatment in theprocesshereinafter described. The. overhead from tower 59', comprising; thebull;A of the. pentane treating agent., hieherhydrocarbons andsubstantially an of the aldelziyde ool-yniersf,` together with smallquantities of alcohols, is transferred through line 28: for use as aWash-oil in. tower 2.5,r in the process; hereinbeiore. described;Makefup quantities 9 of Wash-oil for use in tower 25 are introducedthrough line 63. Y

The bottoms from tower 59 is transferred through line 62 to adistillation tower 64, to effect `the removal of the pentane treatingagent from the alcohol stream. In tower 64 the mixture is 4heated underproper conditions of temperature and pressure, to distill overheadpentane-methanol azeotropes which are withdrawn through line 65. Thepentane-free raffinate is withdrawn as lbottoms through line 66 forfurther treatment in 69 through line '68 with which line 6!)l connects.

Bottoms from separator 61, comprising an aqueous alcohol streamcontaining small quantities of pentane, are transferred through line 69to combine with the extract from tower 59. The

lcombined mixture is transferred through line 62 into tower 64 forfurther treatment in the process hereinbefore described. It should benoted that where so desired, it is'possible to transfer the overheadswithdrawn from tower 32 through line 26 (and which comprise,essentially, methanol and hydrocarbons, as previously described) tocombine with bottoms from tower 59 and separator 61 and entering tower64 through line 62. Conveniently, this is accomplished by passing theove-rheads from tower 32 into line 62 thro-ugh line 16, with whichline-62 connects.

The pentane-free raiiinate, obtained as bottoms from tower 64 in theprocess described above and comprising a mixture of aqueous alcoholshaving up to six carbon atoms per molecule, salts of heayv organicacids, ketones and excess alkali is f transferred throughV line 66 to adistillation tower 1|, which functions as an alcohol stripper. In tower1| the mixture is heated to distill overhead a mixture of alcohols andketones which is withdrawn through line 12. Bottoms from tower 1|,

, comprising an aqueous mixture of salts of heavy organic acids andexcess alkali, are transferred through line 13 for further treatment inthe process hereinafter described. It should be notedfthat it is alsopossible at this point, to transfer the Ycombined bottoms from settler35 and caustic treater 36 (comprising salts of heavy organic acids,alcohols and water) directly into line 66 for treatment in tower 1|, asdescribed above.

Conveniently, this is accomplished by transferring the bottoms thuscombined, through line 14 into line 66 with which line 14 connects.Alternatively, it is possible to transfer the aforementioned stream inline 14, directly into line 51 for treatment in caustic treater 54 inthe process hereinbefore described. This may be accomplished bytransferring the stream in line 14 through line into line 51, with whichline 15 connects. Furthermore, `where so desired, the treated mixture`from caustic treater 54, which is withdrawn through line 56, ashereinbefore described, may be transferred directly into line '66 fortreatment vin y.tower 1l, by-passing towers 59, 6d and separator 66,forremoval of hydrocarbon impurities,

in the manner described above. This may be accomplished by transferringthe stream in line v56 through line 16 into line 66, with whichline 16connects. K

The overheads from tower 1l, comprising an aqueous mixture of alcoholsand ketones, are transferred through line 12 to a distillation tower 11.Intower 11 the mixture is heated to distill overhead a mixture of thelowest boiling alcoholketone components, namely, methanol, acetone andmethyl ethyl ketone, which are withdrawn through line 18. Bottoms fromtower 11, comprising C2 and higher alcohols,` are withdrawn ythroughline 19,1or further treatment in the proc'- ess hereinafter described.The overheads from tower 11, comprising a mixture of methanol, acetone,and methyl ethyl ketone are transferred through line .1B to adistillation tower 80. ,In tower 66 the mixture is heated, under properoperating conditions of temperature and increased pressure, to distilloverhead the lowest boiling Bottoms from tower 89, comprisingmethylethyl ketone, are recovered through line 82.

The vacetone-methanol overhead from towera is transferred through line8| to a distillation tower 83. In tower 83 the mixture is heated, underproper operating conditions of temperature and increased pressure, todistill overhead ace.- tone-methanol azeotropes, which are withdrawnthrough line 84. Bottoms from tower 83, comprising methanol-freeacetone, are recovered through line 85. 'I'he` acetone-methanol azeo.-tropes from tower 83 are transferred through line 84 to a distillationtower 96. Intower 86 the mixture is heated, under proper operatingconditions of temperature and atmospheric pressure, to distill overheadacetone-methanol azeotropes which are withdrawn through line 81. Themixture thus obtained is recycled through line 81 into line 18 for usein tower 89, as described above. Bottoms from tower 86, comprisingmethanol in a substantially pure state, are recovered through line'88.

Bottoms from tower 11, comprising aqueous Cz and higher alcohols, aretransferred through line 19 to a hydrogenation reactor-89. Reactor 89 isprovided for effecting catalytic hydrogenation, by

, conventional methods, of -aldehydes and ketones that may be present inthe alcohol stream obtained as bottoms from tower 11. Hydrogen thusemployed, is introduced into reactor 89 through line 99. As a result ofthe conversion of aldehydes and ketones into alcohols by hydrogenationin reactor 99, the product of the reaction is withdrawn as bottomsthrough line 9i. Bottoms thus Vobtained are cooled and transferredthrough line 9 l toa separator 92. In separator 92, separation isobtained between alcohols, which are withdrawn as bottoms through line93, and hydrogen, which is recycled through line 94 through line 96,with which line 94 connects. At this point, it should be noted thatit isalso possible to transfer aldehydes and ketones present in line 41(obtained in the process hereinbefore described) directly into line 19via line 94V, for conversion into alcohols by catalytic hydrogenation inreactor 89 as described above.

The aqueous mixture of C2 andhigher alcohols i obtained as bottoms fromseparator 92, is transferred through line 93 to a .fractionation tower96. Tower 96 is operated under proper conditions of temperature andpressure effective to distill overhead, aqueous ethanol which isrecovered through 4line 91. Bottoms from tower 96, comprising an aqueousmixtureof Cs and higher alcohols, are withdrawn through line 98.

vthe dehydration of propanol.

is possible at this point to dehydrate the alcohol stream in line 98,through the propanolwater azeotrope. Accordingly, the alcohol stream inline 98 is transferred to a fractionation tower 09., Tower 99 is heatedto distill overhead a propanol-water azeotrope, which is withdrawnthrough line and transferred to a distillation tower |0|. Tower |0| isprovided to effect A dehydrating agent such as benzene, or toluene, isitherefore introduced into tower |0| through line |02, with which line|00 connects. Tower |01 is next heated under conditions effective toobtain water-free propanol as bottoms, which are withdrawn through line|03 for further use outside the scope of this process. A portion of thewater-free propanol, thus obtained, may be transferred from line |03,via line |013, into line 98 Yfor reuse of propanol in effectingsubsequent dehydration of additional quantities of alcohols enteringtower 99 in the process described above.

Overheads from tower |0| comprise water-containing propanol andhydrocarbons. These overheads are withdrawn through line |05, cooled andtransferred to a separator |06. in separator |06, the aqueous propanolhydrocarbon mixture is separated into an upper phase, comprising apropanol-hydrocarbon-water layer, rich in hydrocarbons, which iswithdrawn through line |01, and 'a lower phase, comprising apropanolhydrocarbon-water layer, rich in water, which is withdrawnthrough line |08. The upper Vphase from separator |06 is transferredthrough line |01 into line |00, with which line |01 connects, for reusevof propanol in the process described above. The lower phase fromseparator is transferred through line |08 to a distillation tower |09,vwhich functions as a propanol stripper. Tower |09 is heated to distilloverhead, a water-free propanol-hydrocarbon mixture, which is withdrawnthrough line H0. Bottoms from tower |09, comprising excess water, arewithdrawn through line The overhead from tower |09, comprising awater-free hydrocarbon mixture, is transferred through line l0 into line|01 to combine with the upper phase from separator |06 in line |01. Thecombined propanolhydrocarbon-water stream is then returned to tower |0|through line |01 for further use in the process described above. Bottomsfrom tower 99, comprising C4 and higher alcohols, are withdrawn throughline ||2. These alcohols may be next transferred through line |2 to anyconventional alcohol fractionation system, in which individual C4 andhigher alcohols may be recovered, for further use or treatment outsidethe scope of the present process. Y

As hereinbefore described, there are present in lines 4ll and 95 amixture of aldehydes and ketones. It is, therefore, possible at thispoint to transfer these combined aldehyde-ketone mixtures, via line H3,to a hydrogenation reactor |I4. Reactor ||4 is provided for effectingcatalytic hydrogenation, by conventional methods, of aldehydes andketones present in line H3. Hydrogen thus employed, is introduced intotower Il'll through line H5. As a result of the conversion of aldehydesand ketcnes into alcohols by hydrogenation in reactor I4, the product ofthe V .reaction is withdrawn as bottoms through line IIB. Bottoms thusobtained, are cooled and transferred through line H6 to a separator H1.In separator separation is obtained between C3 'and higher alcoholswhich are withdrawn. as bottoms through line l IB, and hydrogen, whichizA is recycled through line H9 into line |4|5 with which line I0connects. At this point, it is also possible to transfer the upper oillayer from settler 35, in line 30, directly into line H3, via line |20,with which line ||3 connects. In line |20' there is present a mixture ofoxygenated compounds, comprising heavy alcohols, aldehydes, ketones,traces of organic acids, esters, and water. Accordingly, this mixturemay be transferred through line ||3 into reactor H4, in ordery toconvert aldehydes, ketones, esters and acids into alcohols by catalytichydrogenation in the process described above. Bottoms withdrawn fromseparator comprising aqueous C3 and higher alcohols, may be transferred,through line H8, into line 93 to combine with the alcohol streamobtained as bottoms from tower 96. The combined stream may then besubjected to further fractionation and treatment in the processhereinbefore described.

The combined aqueous alcohol stream in line 98, comprising C3V andhigher alcohols, may be subjectedat this point to an alternativedehydration step. Accordingly, this stream in line 98 is transferredthrough line |2|, with which line 98 connects, to a distillation tower|22. An entrainer, such as ethylene dichloride or acetone, is introducedinto tower |22 through line |23. Tower |22 is heated under conditionseffective to absorb in the entrainer, water that is present in thealcohol stream entering tower |22 through line I2|. Following treatmentin tower |22, an overhead comprising a mixture of the entraining agentand water, is withdrawn through line |24. Bottoms from tower |22,comprising dehydrated C3 and higher alcohols, are withdrawn through line|25. The alcohol stream in line |25 is next transferred to afractionation tower |25. Tower |26 is operated under proper conditionsof temperature and pressure effective to distill overhead anhydrous C3alcohols which are recovered through line |21. Bottoms from tower |26,comprising anhydrous C4 and higher alcohols are withdrawn through line|20. The alcohol stream in line |28 may be next transferred into line|2, in which it is combined with C4 and higher alcohols, and transferredto any conventional alcohol fractionation system, in which individual C4and higher alcohols may be recovered for further use or treatmentoutside the scope of the present process.

Overheads from tower |22, comprising a mixture of the entraining agentand water, are cooled and transferred through line |24 to a separator|29. In separator |29 there are present an upper layer, comprising theentraining agent which is withdrawn through line |23, and a loweraqueous layer containing proportionately smaller quantities of theentraining agent, which are withdrawn through line |30. The upper layerfrom separator |29, comprising the entraining agent, is recycled throughline |23 to tower |22 for reuse. Make-up quantities of entraining agentare introduced into line |23 through line |3|, with which line |23connects.

The lower aqueous layer from separator |29, containing proportionatelysmall quantities of entraining agent, is transferred through line |30 toa distillation tower |32. Tower |32 is operated under conditions oftemperature and pressure effective to distill overhead the entrainingagent and small quantities of water, which are withdrawn through line|33. Water obtained as bottoms from tower |32 is withdrawn through line|34. The overhead from tower |32, comprising the entraining agent andsmall quantities of water, may be transferred through line |33 into line|24, with which line |33 connects, for separation of entraining agentand water in separator |29, in the process described above.

As a result of the process, hereinbefo-re described, bottoms from tower1| withdrawn through line 13, comprise an aqueous mixture of salts oforganic acids and excess alkali. In accordance with the process of theinvention, the mixture is subjected to further treatment in order torelease organic acids present in the mixture from their salts. 'I'heaqueous mixture of organic acids and excess alkali is, therefore,transferred through line 13 to a mixer |35. A high boiling inorganicacid having a boiling point higher than that of water, such as sulfuricacid, or an inorganic acid which forms a maximum boiling azeotrope withwater, such as hydrochloric acid, is introduced through line |35 andcombined with the aqueous mixture of organic acids and excess alkali inline 13 which enters mixer |35. Mixer |35 is provided tol inttimatelymix the aqueous alkali mixture of salts of organic acids with theintroduced inorganic acid, in order to effect neutralization of thesesalts. The resulting mixture Afrom mixer |35, comprises free organicacids and salts of the introduced inorganic acid which are withdrawnthrough line |31. The aqueous mixture of free organic acids andinorganic salts is transferred through line |31 to a separator |38. Inseparator |38 the heavier organic acids will separate from the watersolution by reason of their insolubility and will contain a portion ofthe lighter watersolubleV organic acids by reason of the solvent actionof the heavier acids on the lighter acids. These acids, comprising anupper acid-rich phase in separator |38, are withdrawn through `line |39.The lower water-rich phase in separator |38, comprising inorganic salts,the introduced inorganic acid and some of the lighter organic acids, arewithdrawn as bottoms through line |43 and transferred to a distillationtower |4| which functions as an acid stripper. Tower |4| is heated underconditions effective to distill overhead, organic acids as their waterazeotropes, having three or more carbon atoms per molecule. The latterare withdrawn from tower I|4| through line |42 and are thus transferredare withdrawn through line |43 for further use .outside the scope ofthis process.

If so desired, it is possible to transfer the lower water-rich rphasewithdrawn from separator |38 through line y |49, into line |39 via line|44 (by-passing tower |4| and thus combine this phase with the aqueousstream of light organic acids in line 5u, for further use or treatmentin the process hereinafter described. It shouldbenoted, that it is Valsopossible vto transfer the aqueous stream of -lightorganic acids in line59 into line I9, via line |45,.for use in scrubber I8 in the processhereinbefore described.

, vIn order to obtain recovery of water-free or- ',ganic acids, thetotal stream of aqueous organic acids in line is next transferred, inaccordance withdrawn through line |41 for further use in with theprocess of the invention, to an extraction tower |45. In tower |46 thestream introducedthrough line 59, is subjected to intimatecountercurrent contact with a solvent treating agent, such as ethylacetate, which is introduced into tower |45 through line |41. Thetreating agent and the aqueous stream of organic acids, are -contactedin tower |43 under conditions effective to absorb in the treating agenta large proportion of the water contained in the aqueous stream oforganic acids passing through line 50. The extract thus produced,comprises an acid-rich mixture containing organic acids, excess solventtreating agent, and proportionately small quantities of water, and iswithdrawn overhead from tower |46 through line |48. Bottoms from tower|45, comprising a raffinate containing the solvent treating agent andproportionately large quantities of water, arewithdrawn from tower |43through line |49.

The extract from tower |46 comprising an acid-rich mixture containingorganic acids, excess solvent treating agent and proportionately smallquantities of water, is withdrawn overhead through line |48 and istransferred to a distillation tower |59, which functions as a stripperfor the solvent treating agent. Tower |55 is heated under conditionseffective to distill overhead a mixture of the solvent treating agentand water which is withdrawn through line |5|. Bottoms, comprising bothanhydrous light and heavy organic acids, solvent-free, are withdrawnfrom tower |50 through line |52. next transferred through line |52 to afractionation tower |53. Tower |53 is operated under conditions oftemperature and pressure effective to distill overhead substantiallyanhydrous acetic acid, which is withdrawn through line |54. Bottoms fromtower |53, comprising C3 and higher acids may be next transferred,through line |55, to any conventional acid fractionation system in whichindividual C3 and higher acids may be recovered for further use outsidethe scope of this process.

As hereinbefore described, the raffinate from tower |46 -contains thesolvent treating agent fand proportionately large quantities of water.This raffinate is then transferred through line |49 to a distillationtower |56. Tower |56 is heated under conditions of temperature andpressure effective to distill overhead, water-aseotropes of the solventtreating agent which are withdrawn through line |51. Bottoms from tower|55, comprising excess water, are withdrawn thro-ugh line |58. Thewater-azeotropes of the solvent treating agent, which are withdrawnoverhead from tower |55, through line |51, are transferred into line|5|, with which line |51 connects. In line 25|, the overheads from tower|59 are combined with the overheads from tower |50, which comprises a4mixture of the solvent treating agent and water. The combined mixtureis then transferred through line' i 5| to a separator |59. In separator|59 separation is effected between an upper layer, comprising thesolvent treating agent, and a lower water layer, which is withdrawn asbottoms through line |50 and which is transferred via line |49, fortreatment in tower |56 inthe process described above. The upper layerfrom separator |59, comprising the solvent treating agent, is

Make-up solvent These bottoms are acidextraction step, the invention isnot limited sol-ely to itsv use; other solvents may be advantageouslyemployed, such as ethyl ether isopropyl ether,` 'isopropyl chloride andthe like. Ethyl ether may have particular desirability in inystanceslwhere cross-esterication and hydrolysis are-encountered, when ethylacetate is used. as `a solvent. Where suchV is the case. and ethyl etheris used as a solvent, an appreciably larger volume of. solvent would berequired. In order to obtain an anhydrous stream where ethyl ether isused, the ether-water azeotrope can best be removed at a pressure ofapproximately 1GO pounds per square. inch absolute. `In addition` tousing solvents, lower boiling thanthe acids .to be extracted, itis alsopossible to use high bof'ihng alcohols, ketones and organic-,acids inthe process `described above.

It should be noted, that where s-oV desired, it is possible to transferthe upper acid-rich phase in separator |38, directly into tower I| 59-which functions as a solvent stripper in the process described above.Conveniently,` this may be accomplished by transferring theaforementioned upper phase from separator |38 through line It, via lineM8, for treatment in tower |50. Such procedure may have a' particularadvantage, in that thev upper acid-rich phase from separator |38,comprising proportionately larger quantities of the'. heavier organi-cacids than lighter organic acids, may be transferred `directly intotower |50, lby'11f assing the aforementioned solvent extraction step intower |136; the separation step in separator |59 and the distillationstep in tower 55. This procedure is made possible by reason of theheavier organicY acids separating from the water solution in separator|38 because of their insolubility, and containing portions of thelighter water-soluble organic acids by reason of the solvent action ofthe heavier acids on the lighter acids.

an alternative. methodtfor recovering waterfree organic acids from thetotal stream of `aqueous organic acids in line 50, it is possible torecover such water-free acids by means of the solvent actionV of theheavier acids on the lighter acids; Accordingly', the tot-al stream ofaqueous organic acids inline 50 may be transferred, via line lIS2, to anextraction tower |63. In tower |63 the stream introduced through line|52, is subjected to intimate countercurrent contact with one or moreheavier org-anic acids, comprising C7 or high-er organic acids, whichare introduced into tower L63 through line IM as a solvent treatingagent. Thi-s treating agent, conveniently, may be oneor more ofI the C7or higher organic acids which have been recovered from lthe acidfractionation system, into which the stream of organic. acids in line|55 has been introduced, in the pro-cesshereinbeiore described.

T-he solvent .treating agent in line ltd and the total stream of'aqueous organic acids in line |52 are contacted in ltower |53 underconditions effective to absorb in the treating agent, the lighterwater-solubleY acidsv by reason of the solvent action of the heavieracids (solvent treating agent) on the lighter acids. Following treatmentin tower |163, overheads are obtained comprising a mixture of light andheavy organic Iacids and small quantities of'water. These overheads arewithdrawn through line 166. Bottoms yfrom tower |63, comprising -excesswater, are withdrawn through line |181.

The overheads vfrom tower .|i63, comprising a mixtureo-f' light andheavy organic acids :and

small quantitieso water, are transferred through line |66 to adistillation tower |68. Tower |58 is Iprovided to effect dehydration ofacids introduced through line |65. An entrainer, such as ethyl acetate,butyl acetate, ethyl ether, isopropyl ether, isopropyl chloride or. thelike, is introduced in-to -tower It@ through line |69. Tower A|58 isnext heated under conditions eective to absorb in the entraining agent,water that lis present in the organic acid stream entering tower |168.through line Ist. The entraining agent thus used, serves to d-ehydratenot only the aqueous light organic acids introduced into tower |63through line |62, but also effects dehydration of any quantities ofwater that may be present inthe heavier organic acidsv introduced intotower |63 through line,- |54 as the solvent treating agent.

Following treatment in tower |58, :an overhead comprising a mixture ofthe entraining agent and water is withdrawn through line |10. Bottomsfrom tower DB8, comprising dehydrated light and heavy organic acids, arewithdrawn through line |1|. The dehydrated acids in line |1| may next betransferred into line |55, with which line |1| connects, from which theymay be further transferred to any conventional acid `fractionationsystem, in which individual Cs and higher acids are recovered forfurther use, as hereinbefore -describe-d.

The Voverheads from tower D68, comprising a mixture of the entrainingagent and water, are cooled and transferred through line I 'it to'aseparator |12. In separator |12 there lare present an upper layer,comprising th-e entraining agent which is withdrawn through line F69,anda lower aqueous layer containing proportionately smaller quantitiesof the entraining agent, which is withdrawn through line |13. The upperlayer from separator |12, comprising the entraining agent, is recycledthrough line |69 to tower Hi8 for reuse. Make-up quantities ofentraining agent are introduced into line |69, through line |14 withwhich line e|169 connects.

The lower aqueous layer from separator |12, containing proportionatelysmall quantities of en- Itraining agent, is transferred through line |13to a ldistillation tower |15. Tower |15 is operated under conditions oftemperature and pressure effective to distill overhead the entrainingagent and small quantities lof water, which vare withdrawn through line|115. Water obtained as bottoms from tower |15, is withdrawn throughline |11. The overhead -from tower |15, comprising the entraining agentand small quantities of water, may be transferred through line .|126into line i 1B, with which line |16 connects, for separation ofentraining `agent and water in separator 12, in the process describedabove.

To recapitulate, this invention is directed to a process for theseparation of oxygenated organic compounds present in the reactor gasobtained in the catalytic hydrogenation of oxides of carbon, where suchcompounds may comprise, essentially, light and heavyY alcohols andorganic acids, esters, aldehydes, ketones and hydrocarbons. However,while the invention has a particular applicability to the separation ofsuch compounds from the source indicated, the process of the inventionis not necessarily restricted to effecting the desired separation ofthese compounds as derived from the aforementioned source; The processof the invention may be also successfully applied to the separation ofany mixtures of the aforementioned compounds, without regard to thesource from which these mixtures Y 17 may have been derived, and Withoutregard to the composition of such mixtures.

In addition, while a particular embodiment of the invention has beendescribed, for purposes of illustration, it should be understood thatvarious modifications and adaptations thereof, which will be obvious toone skilled in the art, may be made Within the spirit of the inventionas set forth in the appended claims.

I claim:

l. A process for recovering the products of hydrogenation of oxides ofcarbon wherein said products comprise hydrocarbons, organic acids andnon-acid oxygenated organic compounds which comprises cooling saidproducts to effect substantial condensation of normally liquidcomponents to form an oil product liquid phase containing at least aportion of said oxygenated organic compounds and a water product liquidphase, separating said phases, subjecting said oil product liquid phaseto extraction treatment with an aqueous solution of a solvent comprisinga light alcohol to obtain a raiiiinate containing hydrocarbons and anextract containing oxygenated organic compounds, subjecting the extractthus obtained to distillation to obtain a relatively low boilingfraction comprising solvent and a relatively high boiling fractioncomprising oxygenated organic compounds, separating oxygenated organiccompounds from said relatively high boiling fraction, combiningoxygenated organic compounds separated from said relatively high boilingfraction with said water product liquid phase, and subjecting theresulting mixture to distillation to obtain a relatively low boilingfraction comprising non-acid oxygenated organic compounds and arelatively high boiling fraction comprising organic acids.

2. The process of claim 1 in which the solvent is methanol.

3. The process of claim 1 in which the solvent is ethanol.

4. A process for recovering the products of hydrogenation of oxides ofcarbon wherein said products comprise hydrocarbons, organic acids andnon-acid oxygenated organic compounds which comprises cooling saidproducts to effect substantial condensation of normally liquidcomponents to form an oil product liquid phase containing at least aportion of said oxygenated organic compounds and a water product liquidphase, separating said phases, subjecting said oil product liquid phaseto extraction treatment with an aqueous solution of a solvent comprisinga light alcohol to obtain a raffinate containing hydrocarbons and anextract containing oxygenated organic compounds, contacting said extractwith a liquid hydrocarbon wash-oil which is readily separable from saidoxygenated compounds by distillation, subjecting the extract thustreated to distillation to obtain a relatively low boiling fractioncomprising a solvent and a relatively high. boiling fraction comprisingoxygenated organic compounds, separating oxygenated organic compoundsfrom said relatively high boiling fraction, combining oxygenated organiccompounds separated from said relatively high boiling fraction with saidwater product liquid phase, and subjecting the resulting mixture todistillation to obtain a relatively low boiling fraction comprisingnon-acid oxygenated organic compounds and a relatively high boilingfraction comprising oiganic acids.

5. The process of claim 4 in which said Washoil is a hydrocarbon whoseboiling point is substantially Within the boiling range of saidoxygenated organic compounds.

6. The process of claim 4 in which said washoil is a hydrocarbon whoseboiling point is substantially below the boiling range of saidoxygenated organic compounds.

7. The process of claim 4 in which said Washoil is a hydrocarbon havingfrom 5 to 8 carbon atoms per molecule.

8. A process for recovering the products of hydrogen-ation of oxides ofcarbon wherein said products comprise hydrocarbons, organic acids andnon-acid oxygenated organic compounds which comprises cooling saidproducts to effect substantial condensation of normally liquidcomponents to form an oil product liquid phase containing at least aportion of said oxygenated organic lcompounds and a water product liquidphase, separating said phases, subjecting said oil product liquid phaseto extraction treatment with an aqueous solution of a solventcompri-sing methanol to obtain Ia raiinate containing hydrocarbons andan extract containing oxygenated organic compounds, contacting saidextract with pent-ane, subjecting the extract thus tre-ated todistillation to obtain a relatively low boiling fraction Icomprisingsolvent and a relatively high 'boiling fraction comprising oxygenatedorganic compounds, separating oxygenated organic compounds from said-relatively high boiling fraction, combining oxygenated organiccompounds separated from sai-d relatively high boiling fraction .withsaid Water product liquid phase, and subjecting the resulting mixture todistillation to obtain a relatively llow boiling fraction comprisingnon-acid oxygenated organic compounds and a relatively high boilingfraction comprising organic acids.

HENRY G. MCGRATH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,870,816 Lewis Aug. 9, 19321,979,841 Pier et al Nov. 6, 1934 2,076,607 Woodhouse Apr. 13, 19372,083,125 Scheuble June 8, 1937 2,099,475 Giesen et al Nov. 16, 19372,116,081 Pier et al May 3, 1938 2,171,324 Zetzsche et al Aug. 29, 19392,274,750 Soenksen et al May 3, 1942 2,286,814 Kemp June 16, 19422,457,257 Michael etal Dec. 28, 1948 2,470,782 McGrath et al May 24,1949 2,516,940 Arnold et al Aug. 1, 1950 2,533,675 Marschner Dec. 12,1950 FOREIGN PATENTS Number Country Date 446,305 Great Britain Apr. 28,1936 OTHER REFERENCES Koch et al.: Brennstoff Chem. 16, pp, 382-87(1935) l(Photo 260-450).

1. A PROCESS FOR RECOVERING THE PRODUCTS OF HYDROGENATION OF OXIDES OFCARBON WHEREIN SAID PRODUCTS COMPRISE HYDROCARBONS, ORGANIC ACIDS ANDNON-ACID OXYGENATED ORGANIC COMPOUNDS WHICH COMPRISES COOLING SAIDPRODUCTS TO EFFECT SUBSTANTIAL CONDENSATION OF NORMALLY LIQUIDCOMPONENTS TO FORM AN OIL PRODUCT LIQUID PHASE CONTAINING AT LEAST APORTION, OF SAID OXYGENATED ORGANIC COMPOUNDS AND A WATER PRODUCT LIQUIDPHASE, SEPARATING SAID PHASES, SUBJECTING SAID OIL PRODUCT LIQUID PHASETO EXTRACTION TREATMENT WITH AN AQUEOUS SOLUTION OF A SOLVENT COMPRISINGA LIGHT ALCOHOL TO OBTAIN A RAFFINATE CONTAINING HYDROCARBONS AND ANEXTRACT CONTAINING OXYGENATED ORGANIC COMPOUNDS, SUBJECTING THE EXTRACTTHUS OBTAINED TO DISTILLATION TO OBTAIN A RELATIVELY LOW BOILINGFRACTION COMPRISING SOLVENT AND A RELATIVELY HIGH BOILING FRACTIONCOMPRISING OXYGENATED ORGANIC COMPOUNDS, SEPARATING OXYGENATED ORGANICCOMPOUNDS FROM SAID RELATIVELY HIGH BOILING FRACTION, COMBININGOXYGENATED ORGANIC COMPOUNDS SEPARATED FROM SAID RELATIVELY HIGH BOILINGFRACTION WITH SAID WATER PRODUCT LIQUID PHASE, AND SUBJECTING THERESULTING MIXTURE TO DISTILLATION TO OBTAIN A RELATIVELY LOW BOILINGFRACTION COMPRISING NON-ACID OXYGENATED ORGANIC COMPOUNDS AND ARELATIVELY HIGH BOILING FRACTION COMPRISING ORGANIC ACIDS.